COMMISSION IMPLEMENTING REGUL ATION (EU) 2020/229 
of 19 Febr uary 2020 
concer ning the author isation of L-tryptophan as a feed additiv e for all animal species 
(Text with EEA relevance) 
THE EUR OPEAN COMMISSION, 
Havi ng regar d to the Treaty on the Functioning of the European Union, 
Havi ng rega rd to Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 Sept ember 2003 on 
additives for use in animal nutr ition (1), and in particular Article 9(2) thereof, 
Whereas: 
(1) Regulation (EC) No 1831/2003 provid es for the author isation of additives for use in animal nutr ition and for the 
grounds and procedures for granting such author isation. 
(2) In accordance with Article 7 of Regulation (EC) No 1831/2003 applications were submitted for the author isation of 
L-tryptophan produced by Escher ichia coli KCCM 80135, Escher ichia coli KCCM 80152, Escher ichia coli CGMCC 7.248 
or Corynebacter ium glutamicum KCCM 80176. These applications were accompan ied by the particulars and 
documents required under Article 7(3) of that Regulation (EC). 
(3) The applications concer n the author isation of L-tryptophan produced by Escher ichia coli KCCM 80135, Escher ichia coli 
KCCM 80152, Escher ichia coli CGMCC 7.248 or Corynebacter ium glutamicum KCCM 80176 as a feed additive for all 
animal species, to be classif ied in the additive categor y ‘nutr itional additives’. 
(4) The European Food Safety Author ity (‘the Author ity’) concluded in its opinions of 22 Januar y 2019 (2), 2 Apr il 
2019 (3), 3 Apr il 2019 (4) and of 16 May 2019 (5) that, under the proposed conditions of use, L-tryptophan 
produced by Escher ichia coli KCCM 80135, Escher ichia coli KCCM 80152, Escher ichia coli CGMCC 7.248 or 
Corynebacter ium glutamicum KCCM 80176 does not have an adverse effect on the health of non-r uminant animal, 
consumer safet y or the environment. To be safe for ruminants, the L-tryptophan should be prot ected against 
degradation in the rumen. The Authority stated a risk for the users of the additive upon inhalation due to the 
endoto xin levels of the L-tryptophan produced by Escher ichia coli KCCM 80152 and Escher ichia coli CGMCC 7.248. 
Theref ore, the Commission considers that appropr iate prote ctive measures should be take n to prevent adverse 
effects on human health, in particular as regar ds the users of the additive. The Author ity considered L-tryptophan 
produced by Escher ichia coli KCCM 80135, Escher ichia coli KCCM 80152, Escher ichia coli CGMCC 7.248 or 
Corynebacter ium glutamicum KCCM 80176 an efficacious source of the essential amino acid tryptophan for non- 
ruminant animals; for the supplemental L- tryptophan to be fully efficacious in ruminants, it should be prot ected 
against degradation in the rumen. The Auth ority does not consider that there is a need for specific requirements of 
post-market monitoring. It also verified the repor t on the method of analysis of the feed additive in feed submitted 
by the Reference Laboratory set up by Regulation (EC) No 1831/2003. 
(5) The assessment of L-tryptophan produced by Escher ichia coli KCCM 80135, Escher ichia coli KCCM 80152, Escher ichia 
coli CGMCC 7.248 or Corynebacter ium glutamicum KCCM 80176 shows that the conditions for author isation, as 
provid ed for in Article 5 of Regulation (EC) No 1831/2003, are satisfi ed. According ly, the use of that substance 
should be author ised as specified in the Annex to this Regulation. 
(6) The measures provid ed for in this Regulation are in accordance with the opinion of the Standing Committ ee on 
Plants, Animals, Food and Feed, 
(1)OJ L 268, 18.10.2003, p. 29. 
(2)EFSA Jour nal 2019;17(2):5601. 
(3)EFSA Jour nal 2019;17(5):5694. 
(4)EFSA Jour nal 2019;17(5):5695. 
(5)EFSA Jour nal 2019;17(6):5729. EN Offi cial Jour nal of the European Union 20.2.2020                                                                                                                                            L 47/5   HAS ADOPTED THIS REGUL ATION: 
Article 1 
The substance specifi ed in the Annex, belonging to the additive categor y ‘nutr itional additives ’ and to the functional group 
‘amino acids, their salts and analogues’, is author ised as an additive in animal nutr ition subject to the conditions laid down 
in that Annex. 
Article 2 
This Regulation shall enter into force on the twentieth day followi ng that of its publication in the Official Journal of the 
European Union. 
This Regulation shall be binding in its entirety and directly applicable in all Member States. 
Done at Brussels, 19 Febr uary 2020.  
For the Commission 
The President 
Ursula VON DER LEYEN     EN Offi cial Jour nal of the European Union L 47/6                                                                                                                                            20.2.2020   ANNEX 
Identification 
number of the 
additive Name of the 
holder of 
author isation Additive Composi tion, chemical formula, 
descr iption, analytical method. Species or 
categor y of 
animal Maximum 
age Minimum 
conten t Maximum 
conten t 
Other provisions End of period of 
author isation mg/kg of compl ete feed with a 
moisture content of 12 % 
Categor y of nutr itional additiv es. Functional group: amino acids, their salts and analogues. 
3c441 - L-tryptophan Additiv e composition: 
Powder with a minimum of 98 % 
L-tryptophan (on a dry matter ba­
sis). 
Maximum content of 10 mg/kg 
1,1′-eth ylidene-bis-L-tr yptophan 
(EBT). All species - - - 1. L-tryptophan may be placed 
on the mark et and used as an 
additive consisting of a pre­
paration. 
2. For users of the additive and 
premixtures, feed business op­
erators shall establish opera­
tional procedures and organi­
sational measures to address 
potential risks by inhalation, 
dermal contact or eyes con­
tact. Where those risks cannot 
be eliminated or reduced to a 
minimum by such procedures 
and measures, the additive and 
premixtures shall be used with 
personal prot ective equip­
ment, including breathing 
protection, safety glasses and 
gloves. 
3. The endoto xin content of the 
additive and its dusting pote n­
tial shall ensure a maximal en­
doto xin exposure of 1600 IU 
endoto xins/m3 air (1). 
4. L-tryptophan may be used via 
water for drinking. 
5. For ruminants, L-tryptophan 
shall be rumen protect ed. 
6. The labelling of the additive 
shall indicate the moisture 
content. 11.3.2030 
Character isation of the activ e 
subst ance: 
L-tryptophan produced by fer­
mentation with Escher ichia coli 
KCCM 80135 or 
Escher ichia coli KCCM 80152 or 
Escher ichia coli CGMCC 7.248 or 
Corynebacter ium glutamicum 
KCCM 80176. 
Chemical formula: C11H12N2O2 
CAS No: 73-22-3 
Analytical methods (2): 
For the identif ication of L-trypto­
phan in the feed additive: 
—Food Chemical Codex ‘L-tryp­
toph an monograph’. 
For the determination of trypto­
phan in the feed additive and pre­
mixtures: 
— High performa nce liquid 
chromat ography with fluor­
escence detec tion (HPLC- 
FLD) – EN ISO 13904 
For the determination of trypto­
phan in compo und feed and feed 
mat erials: EN Offi cial Jour nal of the European Union 20.2.2020                                                                                                                                            L 47/7   Identification 
number of the 
additive Name of the 
holder of 
author isation Additive Composi tion, chemical formula, 
descr iption, analytical method. Species or 
categor y of 
animal Maximum 
age Minimum 
conten t Maximum 
conten t 
Other provisions End of period of 
author isation mg/kg of compl ete feed with a 
moisture content of 12 % 
7. The labelling of the additive 
and premixtures shall indicate 
the followi ng: 
‘The supplementation with L- 
tryptophan, in particular via 
water for drinking, should take 
into account all essential and 
conditional essential amino 
acids in order to avoid imbal­
ances.’ — High Performance Liquid 
Chromat ography with fluor­
escence detec tion (HPLC- 
FLD) – Commission Regula­
tion (EC) No 152/2009 (An­
nex III, G) 
For the determination of trypto­
phan in water: 
— High performa nce liquid 
chromat ography with fluor­
escence detec tion (HPLC-FL D) 
(1) Details of the analytical methods are avail able at the follo wing address of the Reference Laboratory : https://ec.europa.eu/jrc/en/eurl/feed-additives/evaluation-repor ts 
(2) Exposure calculated based on the endoto xin level and the dusting potential of the additive according to the method used by EFSA (EFSA Jour nal 2017;15(3):4705); analytical method: European Phar macopoeia 
2.6.14. (bacterial endoto xins).   EN Offi cial Jour nal of the European Union L 47/8                                                                                                                                            20.2.2020